Dors Junior, Oli LuizValerdi, MabelRiffel, Rogemar A.Riffel, RogérioCardaci, Mónica VivianaHägele, Guilhermo F.Armah, MarkRevalski, MitchellFlury, SophiaLemes, Priscila FreitasAmôres, EduardoKrabbe, Angela CristinaBinette, LucFeltre, AnnaBergmann, Thaisa Storchi2025-02-122025-02-12https://repositorio.univap.br/handle/123456789/570For the first time, the sulphur abundance relative to hydrogen (S/H) in the narrow-line regions of a sample of Seyfert 2 nuclei (Sy 2s) has been derived via direct estimation of the electron temperature. Narrow emission-line intensities from the Sloan Digital Sky Survey (SDSS) Data Release 17 (DR17) [in the wavelength range 3000 < λ(Å) < 9100] and from the literature for a sample of 45 nearby (z < 0.08) Sy 2s were considered. Our direct estimates indicate that Sy 2s have similar temperatures in the gas region where most of the S+ ions are located in comparison with that of star-forming regions (SFs). However, Sy 2s present higher temperature values (∼10 000 K) in the region where most of the S2+ ions are located relative to that of SFs. We derive the total sulphur abundance in the range of 6.2 􏰀 12 + log(S/H) 􏰀 7.5, corresponding to 0.1–1.8 times the solar value. These sulphur abundance values are lower by ∼0.4 dex than those derived in SFs with similar metallicity, indicating a distinct chemical enrichment of the interstellar medium (ISM) for these object classes. The sulphur abundance relative to oxygen (S/O) values for our Sy 2 sample present an abrupt (∼0.5 dex) decrease with increasing oxygen abundance relative to hydrogen (O/H) for the high-metallicity regime [12 + log(O/H) 􏰁 8.7)], what is not seen for the SFs. However, when our Sy 2 estimates are combined with those from a large sample of SFs, we did not find any dependence between S/O and O/H.PDFen-USArtigos de PeriódicosOli Luiz Dors JuniorMabel Valerdi10.1093/mnras/stad635GalaxiesEvolution – galaxiesActive – galaxiesSeyfertDORS JUNIOR, Oli Luiz et al. Chemical abundances in Seyfert galaxies – X. Sulphur abundance estimates. Monthly Notices of the Royal Astronomical Society, v. 521, n. 2, p. 1969-1987, 2023. Disponível em: https://academic.oup.com/mnras/article/521/2/1969/7068106.Universidade do Vale do ParaíbaInstituto Nacional de Astrofísica, Optica y ElectrónicaUniversidade Federal de Santa MariaUniversidade Federal do Rio Grande do SulUniversidad Nacional de La PlataSpace Telescope Science InstituteUniversity of Massachusetts AmherstUniversidade Estadual de Feira de SantanaUniversidad Nacional Autónoma de MéxicoUniversité LavalOsservatorio di Astrofisica e Scienza dello Spazio di Bologna